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/*
* src/record.c
* (c) 2021 Jonas Gunz <himself@jonasgunz.de>
* License: MIT
*/
/* https://datatracker.ietf.org/doc/html/rfc1035#section-3.3 */
#include "record.h"
/*
* Prototypes for rdata from string functions
* Arguments:
* _str: String representing rdata
* _rdata: A buffer containing the raw rdata will be alloced here
* Return: Length of alloced _rdata buffer, <0 on error
*/
/* Obsolete record types. Will throw error. */
static ssize_t record_rdata_obsolete(char* _str, void** _rdata);
/* Unimplemented record types. Will throw error. */
static ssize_t record_rdata_not_implemented(char* _str, void** _rdata);
/* rdata that does not need conversion from string form */
static ssize_t record_rdata_verbatim(char* _str, void** _rdata);
/* rdata from fqdn to qname */
static ssize_t record_rdata_qname(char* _str, void** _rdata);
/* IPv4 Addresses */
static ssize_t record_rdata_a(char* _str, void** _rdata);
/* Start of authority */
static ssize_t record_rdata_soa(char* _str, void** _rdata);
static const char* const record_types[] = {
"A",
"NS",
"MD",
"MF",
"CNAME",
"SOA",
"MB",
"MG",
"MR",
"NULL",
"WKS",
"PTR",
"HINFO",
"MINFO",
"MX",
"TXT"
};
static const uint16_t record_types_len = sizeof(record_types) / sizeof(char*);
static ssize_t (*record_rdata_creator[])(char*, void**) = {
&record_rdata_a, /* A */
&record_rdata_qname, /* NS */
&record_rdata_obsolete, /* MD */
&record_rdata_obsolete, /* MF */
&record_rdata_qname, /* CNAME */
&record_rdata_soa, /* SOA */
&record_rdata_not_implemented,
&record_rdata_not_implemented,
&record_rdata_not_implemented,
&record_rdata_not_implemented,
&record_rdata_not_implemented,
&record_rdata_not_implemented,
&record_rdata_not_implemented,
&record_rdata_not_implemented,
&record_rdata_not_implemented,
&record_rdata_verbatim, /* TXT */
};
static const char* const record_classes[] = {
"IN",
"CS",
"CH",
"HS"
};
static const uint16_t record_classes_len = sizeof(record_classes) / sizeof(char*);
/* Implementation of RDATA cobverters */
static ssize_t record_rdata_obsolete(char* _str, void** _rdata) {
LOGPRINTF(_LOG_ERROR, "Record type not obsolete");
return -1;
}
static ssize_t record_rdata_not_implemented(char* _str, void** _rdata) {
LOGPRINTF(_LOG_ERROR, "Record type not implemented");
return -1;
}
static ssize_t record_rdata_verbatim(char* _str, void** _rdata) {
size_t len;
if ( !_str || !_rdata )
return -1;
len = strlen(_str) + 1; /* Including \0 */
*_rdata = malloc(len);
if ( !*_rdata )
return -1;
strncpy(*_rdata, _str, len);
return (signed) len;
}
static ssize_t record_rdata_qname(char* _str, void** _rdata) {
size_t len;
size_t qlen;
if ( !_str || !_rdata )
return -1;
len = strlen(_str); /* Including \0 */
qlen = len + 1;
if (fqdn_check(_str, len) < 0) {
LOGPRINTF(_LOG_ERROR, "Not a valid FQDN");
return -1;
}
/*
* TODO Some funny business is going on around here
* Related to fqdn_to_qname()
*/
*_rdata = malloc(qlen+1);
if ( !*_rdata )
return -1;
/*strncpy(*_rdata, _str, len);*/
fqdn_to_qname(_str, len, *_rdata, qlen);
return (signed) qlen;
}
static ssize_t record_rdata_a(char* _str, void** _rdata) {
char* tok;
char* str;
char* end;
size_t len;
int i;
if ( !_str || !_rdata )
return -1;
len = strlen(_str) + 1;
str = malloc(len);
strncpy(str, _str, len);
*_rdata = malloc(4);
if ( !*_rdata )
return -1;
tok = strtok(str, ".");
if( !tok )
goto err;
((uint8_t*)(*_rdata))[0] = (uint8_t) strtol(tok, &end, 10);
if( *end != '\0' )
goto err;
for( i=1; i<4; i++) {
tok = strtok(NULL, ".");
if( !tok )
goto err;
((uint8_t*)(*_rdata))[i] = (uint8_t) strtol(tok, &end, 10);
if( *end != '\0' )
goto err;
}
free(str);
return 4;
err:
free(str);
return -1;
}
static ssize_t record_rdata_soa(char* _str, void** _rdata) {
LOGPRINTF(_LOG_ERROR, "Record type not implemented");
return -1;
}
/* Other methods */
static uint16_t record_match_from_array(char* _str, const char* const _arr[], uint16_t _len) {
uint16_t i;
for( i=0; i<_len; i++ ){
if ( strcasecmp( _str, _arr[i] ) == 0 )
return i+1; /* Indices start with 1 */
}
return 0;
}
uint16_t record_class_from_str(char* _str) {
return record_match_from_array(_str, record_classes, record_classes_len);
}
uint16_t record_type_from_str(char* _str) {
return record_match_from_array(_str, record_types, record_types_len);
}
ssize_t record_rdata_from_str(void** _rdata, char *_str, uint16_t _rdtype) {
uint16_t index;
if ( _rdtype > record_types_len )
return -1;
if ( !_rdata || !_str )
return -1;
index = _rdtype - 1;
return (*record_rdata_creator[index])(_str, _rdata);
}
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